The present invention concerns a process for manufacturing a fraction comprising carboxylic acid anhydride by reaction of a fraction comprising carboxylic acid with a ketene, and the use of the fraction comprising carboxylic acid anhydride in a process for acylation of polysaccharides.

The present invention concerns a process for manufacturing a fraction comprising carboxylic acid anhydride by reaction of a fraction comprising carboxylic acid with a ketene, and the use of the fraction comprising carboxylic acid anhydride in a process for acylation of polysaccharides.

An object is to provide a method for producing a ketene derivative that decreases the consumption quantity of phosphorus compounds, and the discharge quantity of the phosphorus compounds into the environment.

A method for producing a ketene derivative includes a step (i) of conducting thermal decomposition reaction of acetic acid in a presence of a phosphorus-containing catalyst in a reactor to produce a thermal decomposition gas containing ketene, a step (ii) of cooling the thermal decomposition gas to be separated into a gaseous component containing ketene, and a condensed liquid containing a phosphorus compound (a), and a step (iii) of causing the ketene to react with a different organic compound to produce a ketene derivative. The step (i) includes conducting the thermal decomposition reaction while supplying, into the reactor, the condensed liquid containing the phosphorus compound (a) or a concentrated liquid of the condensed liquid.

An object is to provide a method for producing a ketene derivative that decreases the consumption quantity of phosphorus compounds, and the discharge quantity of the phosphorus compounds into the environment.

A method for producing a ketene derivative includes a step (i) of conducting thermal decomposition reaction of acetic acid in a presence of a phosphorus-containing catalyst in a reactor to produce a thermal decomposition gas containing ketene, a step (ii) of cooling the thermal decomposition gas to be separated into a gaseous component containing ketene, and a condensed liquid containing a phosphorus compound (a), and a step (iii) of causing the ketene to react with a different organic compound to produce a ketene derivative. The step (i) includes conducting the thermal decomposition reaction while supplying, into the reactor, the condensed liquid containing the phosphorus compound (a) or a concentrated liquid of the condensed liquid.

Disclosed is the integration of the production of acetic anhydride from ketene, and the acetylation of wood using acetylation fluid comprising acetic acid and acetic anhydride. The invention involves directly using raw acetic anhydride as obtained in the production thereof from ketene, as a wood acetylation fluid.

Disclosed is the integration of the production of acetic anhydride from ketene, and the acetylation of wood using acetylation fluid comprising acetic acid and acetic anhydride. The invention involves directly using raw acetic anhydride as obtained in the production thereof from ketene, as a wood acetylation fluid.

The present invention concerns a process for manufacturing a fraction comprising carboxylic acid anhydride by reaction of a fraction comprising carboxylic acid with a ketene, and the use of the fraction comprising carboxylic acid anhydride in a process for acylation of polysaccharides.

The present invention concerns a process for manufacturing a fraction comprising carboxylic acid anhydride by reaction of a fraction comprising carboxylic acid with a ketene, and the use of the fraction comprising carboxylic acid anhydride in a process for acylation of polysaccharides.

The present invention discloses a method of producing potassium sorbate particles, comprising the steps of: (1) preparing a potassium sorbate solution; (2) spray drying; (3) spray forming; (4) indirectly drying with steam on a vibration fluidized bed; and (5) swing-type sifting; in step (3), a binder is obtained by spray drying after adding sorbitol to the potassium sorbate solution prepared in step (1), and the binder is mixed with the potassium sorbate powder obtained by spray drying in step (2) to undergo the spray forming process; based on weight ratio, the weight ratio of the sorbitol required to prepare the binder to the potassium sorbate solution required to prepare the binder is 0.05-0.1%:1. The beneficial effects of the present invention are: an appropriate binding effect of the powder particles, a good breaking effect and a good spheronization effect of the powder particles, and uniformity of granulation.

The present invention discloses a method of producing potassium sorbate particles, comprising the steps of: (1) preparing a potassium sorbate solution; (2) spray drying; (3) spray forming; (4) indirectly drying with steam on a vibration fluidized bed; and (5) swing-type sifting; in step (3), a binder is obtained by spray drying after adding sorbitol to the potassium sorbate solution prepared in step (1), and the binder is mixed with the potassium sorbate powder obtained by spray drying in step (2) to undergo the spray forming process; based on weight ratio, the weight ratio of the sorbitol required to prepare the binder to the potassium sorbate solution required to prepare the binder is 0.05-0.1%:1. The beneficial effects of the present invention are: an appropriate binding effect of the powder particles, a good breaking effect and a good spheronization effect of the powder particles, and uniformity of granulation.